Repair of Oxidizing Hydroxyl Adduct Radicals of DNA Bases by Hydroxyl‐trans‐Stilbenes via Single Electron Transfer

Abstract

Repair of oxidizing hydroxyl adduct radicals of DNA bases (base-OH-adduct) by eleven hydroxyl-trans-stilbenes via single electron transfer under physiological conditions are investigated using density functional theory. For eleven hydroxyltrans-stilbenes (PSOHs), their anions make all the contributions to repairing oxidizing base-OH-adduct radicals. Ten PSOHs show better beneficial antioxidant effect than trans-resveratrol. 3, 3', 4, 4', 5, 5'-Hexahydroxy-trans-stilbene (PSOH d ) performs the best repair activity to oxidizing base-OH-adduct radicals, and 3', 4', 5, 5'-tetrahydroxy-trans-stibene has the smallest pK a value. The rate constants for the reactions of PSOH d with oxidizing base-OH-adduct radicals are about 10 5 ∼ 10 9 dm 3 mol À 1 s À 1 . Main factors affecting the repair reactions are the vertical ionization potential, the pK a of PSOHs and the vertical electron affinity of oxidizing base-OH-adduct radicals. This study gives information on repairing oxidizing base-OH-adduct radicals by PSOHs in biological environment for the first time and finds more beneficial antioxidant effect polyphenol than trans-resveratrol or piceatannol.